Sz- Biological explanation

Question 1

What is a recent estimate for the heritability of Sz?

Answer 1

79%

Question 2

What does the deletion of the COMT gene mean?

Answer 2

This would mean that dopamine levels are poorly regulated resulting in schizophrenic symptoms.

Question 3

What causes the DiGeorge Syndrome? And what percentage of people with these syndrome get SZ?

Answer 3

• The deletion of around 30-40 neighbouring genes located in a specific region of chromosome 22
• As many as 25%

Question 4

What is the diathesis stress model?

Answer 4

Proposes that stress, through its effects on cortisol production, acts upon a preexisting vulnerability to trigger and/or worsen the symptoms of schizophrenia.

Question 5

How many times greater are people with an abnormality to the gene DISC1 to get SZ?
What does this gene code for?

Answer 5

• 1.4
• GABA

Question 6

What did Gottesman and Shields identify the concordance rate to be between twins in SZ?

Answer 6

MZ- 42%
DZ- 9%

Question 7

Why should you be careful when interpreting results from MZ/DZ twin studies?

Answer 7

Mz are likely to be treated the same as they look similar and therefore have the same environmental factors

Question 8

What did Pedersen and Mortensens reseach show about SZ?

Answer 8

The longer that people are exposed to city life and the denser the population of the city - the greater their risk of developing SZ

Question 9

What is a strength of the genetic approach in SZ?

Answer 9

Used to inform genetic counselling- the family of a sz may want to know if it is heritable